Did my FrankenPre last weekend, and I took the shortcut route.
To summarize: use Save/Restore app to copy out as many app settings as possible on the Pre-, copy all the files off the Pre- USB partition, put the Pre- in airplane mode and shut down, remove battery cover & battery, remove the 6 T5 screws, unsnap the keyboard border, unsnap the 2 GPS wires, rotate the bezel ~90 degrees carefully with the volume cables attached, pop off the radio board on the Pre-, repeat all the prior steps for the Pre2, carefully press the Pre- radio onto the Pre2, replace bezel, reattach GPS wires, reconnect keyboard border, screw everything down, then run the VZW Pre2 WebOS 2.1 doctor.
- Definitely watch the video walkthroughs. I watched 2 different ones for different camera angles. The keyboard border removal is the most complicated and tricky step because everything feels so delicate when disassembled.
- You may be tempted not to run the VZW doctor again b/c the Pre2 will be able to make calls, use 3G and send email but you won't be able to use SMS and will likely act weird when hanging up, getting voice mail alerts, or any other carrier network messages, likely due to the tokens. So just run the doctor again.
- make sure you get the battery pull-strap out of the way or your headset jack will not work as it blocks the contacts. Sigh.
- Remember that to Doctor a functional device, you have to boot the phone while holding the VOLUME UP button to get it in USB restore mode. I spent 6 hours trying to get the Doctor to work, removing NovaCom drivers, rebooting my PC, etc.
- Save/Restore & data backup ahead of time and get the DB3 database in case you want to extract any SMS messages.
- setting airplane mode before you shut down is handy in case you need to try to get something off your Pre-. Without network access, you won't run into issues when 2 phones try to access the same profile.